Light signal



s. M; DAY

LIGHT SIGNAL Filed March 2,

May 21, 1935.

1925 2 Sheets-Sheet 1 May 21, 1935."

FIGS.

s. M. DAY 2,002,471

LIGHT SIGNAL 2 Sheets-Sheet 2 Filed March 2, 1925 4 ATTORNEY Indescribing the invention in Patented May 21, 1935 DF'FICE ightw gt-.112; 19.25,; smsurulasaz a (c1'., ;iv 'sz9) This invention relates'towayside signals for railways and more specifically concerns a colorlight wayside signal embodying lightconcentrating means of the reflectortype. h

Color light signals for use iny-rai work are designed to projects.concentrated light beam along the trackway, the. color or other aspectof this light being an indication of the traffic conditions ahead It isdesirable that such a signal may project a beam which is clearlydistinguishable at -a.gcomparatively long range,

such as 3000 or 4000 .feet even by daylight under the most unfavorableconditions of light and background, andthat ;the energyconsumption ofthe signal bea minimum @It is also desirable to provide for a readyinspection of the light-projecting unit in order that it may be easilyand quickly l n e d and focus d-a With the above and otherconsiderations in mind, it is proposed in accordancewith the presentinvention to provide a color light signal of the-"type employingacombined reflecting. and retracting means which will utilize a maximumamount of the light emerging from the light source, and to provide amounting for this remeans and light sourcewhich willfacilitote theinspectionand maintenance of such refleeting means and source,and.;will.permit relative adjustment oi the source and the reflectingmeans for focus. i V

Other objects and advantageous features of the present invention willbecome apparent as the description thereof progresses,

detail, reference will be madeto theacco npanying drawings, in

.which:--

l .H M Fig 1 shows a sectional side view of the light signal embodyingthe present invention together with a supporting means therefor;

door removed, certainportions of the devicebeing broken away forclearness; 3 is a section takenon the line 3-4 of Figs. 1 and .2, viewedin the directionoifthe arrows;I. M Figl .4 is a section taken on theline. 4-4 of Fig. 2, viewed in the direction of the arrows'i Fig. 5 is asectional side view of a modif ed form of the mirror supporting meanslorthelight' signal of the present invention; and g Fig. 6 is a sectiontaken, on the line 6f 6 of Fig; 5 and viewed in the direction ofthearrows. Referring to the drawings; the light signal comprises theusual casing C provided-'witha large opening 2 in its front faceand-small openings 3 lway signal 2 showsla rear View pfthe i mi it t orhood 2611s secured to the structure s over the and 4 inits top andbottoin walls respectively. 'I'hecasing-Cmay'be secured to any suitablesupport, andfromne of illustration has been shown mounted on a capmember 5 which is adjust-ably secured to a. signal post or othersuitable 5 structure by means of the set screws 1, the casing C being'adjustably secured to the ca memher 5 by means of the; bolts 8 in amanner which is readily apparent from the drawings. A rear cover or door9 is provided on the casing C, being 10 secured in place by suitablehinges l0, and a hasp H, andbeingprovided with agasket l2, carried inagroove at the edge of thedoor 9 and adapted mm tightly against theedges of the casing C holes bythe boltst as shown. y

' A supporting struc 'S for the lightprojecting unit is secured tothe'casing C at the large opening 2 in its front wall. This structure 3comprises an outwardly projecting tubular portion 'ls havingacircularopening 20 and carrying a. flange l8, and a rearwardly projecting shelfportiori 2|. The structure Sis secured to the casing C by meansof thebolts 11 passing through holes in the flanges l8 as'shown. An outer lensor color screen'n, comprising a. plain glass having a dis- 35 tinctivecolor or other aspect isiitted at its edges in a .rabbet or groove 23 inthe opening 20 of the structures, the color screen 22 being held inplace by the ring and the screw bolts 25. VA shield .are secured to thesupporting structure S by means of a bracket B; This bracket B is ofirregular shape as most clearly shown in Fig. 1, having ahorizontal-base portion 29 and a rear wall 30, a, portionofthis wall '30being arranged at an angle to'the vertical as shown at 3|. The bracket Bis securedto the shell. portion 2| of the supporting structure by meansof the screws as shown.

Two ears 33 extend upwardly from the side walls 34 of the bracket B, andare provided with aligned horizontal openings. A mirror frame 35,provided with integral ears 36 is pivoted to the bracket B the screws42, the free ends of these latches extending above the walls 34 "andbeing bent out wardly as clearly shown in Fig. 2. Small pins 43 (seeFig. 4) extend horizontally from opposite edges of the frame 35, andwhen theframe is in 3 its vertical position, these pins engagecorresponding holes in the latches 4|,thus latching the frame 35 in itsoperative position. When it ,is desired to tilt the frame 35-backwardfor cleaning, replacing the lamp, or inspectingthe mirror,

the spring latches 4| are drawn outwardly-, re-; leasing the pins 43 inthe frame35,-and permit ting the frame to be swungv tea horizontalpositionaboutthe bolts 31. 1 V

- The light bulb 28 is supported within the mirror, 21,.on an adjustablebase D, the filament of the bulb .28 being arrangednear'thefocal pointof the mirror. The base D hasa forked extension 44 which rests upon thelower face of the cylindrical portion of the SuDDQrting structure- ,8,straddlingan eye bolt45as clearly shown in Figs. 1 and 3. .Anadjustingscrew 46 is rigidly secured to avertical extension 41 of the baseDandextends rearwardly through a vertical straightslot .48; (-Figs. 1and-3) in the wall 3| of the bracket B. A plate 49 is adjustably securedto the rear wall 3| of the bracket B by a'thumb screw 50 passing througha horizontal straight slot (Figs; 2 and 4) in. this plate as shown, andthe adjusting screw 46 passes snugly slidable through a circular hole intheplate 49 and is-provided with a wing nut 52. A coiled spring 53iscOnnected between an angular vertical extension 54 of the base D andthe eye bolt 45, and" acts to urge the base D forward, drawing the wingnut 52fagainst the plate 49. By turning the wing'nut 52, the base D'maybe moved in .a horizontal plane against the pull of the spring 53, andby loosening the thumb screw 50, the plate 49 may be shifted on thebracket B in a direction parallel withvertical slot 48 while turning onscrew 50 as a slidable pivot in horizontal slot 5| to'any positionwithin the limits of the slots 48'and5 somoving the ad justing screw 46and the base D ina substantially vertical plane. f a f A light socketsupport 55 is secured to insulating 'posts56 on the vertical extension54 of the base D as shown. The upper'end of the'support 55. is bent intosemi circular shape and is soldered, welded, or otherwisesuitablysecured to a lamp socket 51 which is thereby held in a horizontalposition. The central contactof the socket 51 is provided with asuitable. connecter 58, and -a wire 59 is electrically connected to thesupport 55 by a screw 60; The wires for supplying energy to the lightbulb have been shown broken away, but it is assumed that these wireswill pass through the opening 4.in; the lower wall of the casing C,through the hollow cap 5 and the signal post ,6 to some suitable circuitcontrolling meansand source of energy. a

The mirror 21 is of the combined reflecting and refracting type, and asthe particular construction of this mirror forms no part of the presentinvention, only a brief description of its structure and operation willbe given. The mirror is semispherical in form and is mirrored on itsrear or convex surface so that the light passes through the glass beforebeing reflected. The glass is of varying thickness as shown, and is soarranged with'respect to the filament of the light bulb 28 that thelight emerging from this filament is concentrated into a well definedbeam. It should be particularly noted that the shape of the mirror 21and the location of the light bulb 28 within it are such ,that a largespherical angle of the light emerging fromthe'filament of the bulb isutilized,

and for thisreason the'light projecting unit is These focus markers mayconsist of short radially spacedparallel lines painted on the innersurface of the color screen 22, or small strips of paper or othersuitable material having parallel lines marked thereon may be glued orotherwise suitably secured to this surface, or may be secured to thering 24 by means of rivets as shown,

three of these markers being provided at subthe wing nut 52. In thismanner, the light beam may be quickly and accurately focused.

InFigs. 5 and 6, a modified form of supporting' means for the mirror 21has been shown, this modification including a means for adjusting theposition in which the mirror supportingframe 35 is held when in itsoperating position. In this modification, the rearwardly projectingshelf portion 2| of the supporting structure S carries a bracket B whichis slightly different in construction from'the bracket B of the formshown in Figs. 1 through 4, the bracket B having an extended baseportion 63 provided with two upwardly extending bosses 64 at its sidesas clearly shown in Fig. 6. These bosses 64 are arranged directly underthe position occupied by the front edge of the mirror frame 35 when initsupright position, and carry set screws 65 provided with lock nuts 66,the heads of the set screws being arranged to act as stops for the frame35 when in its upright position. It is evident that by adjusting thepositions of the set screws 65, the angle at which the frame 35 with itsassociated mirror 21 stands with regard to the light source and lens maybe readily adjusted. The set screws '65 are easily accessible for suchadjustment when the mirror 21 is swung backward to its horizontalposition.

A modified type of mirror retaining means has been shown :in connectionwith Figs. 5 and 6,this means comprising two metallic strips 61 whichare pivotally secured at their upper ends to theears 36 of the mirrorframe 35 bymeans of the ma.- chine screws 68. The strips 61 are providedwith elongated slots 69 extending from their midpoints nearly to theirlower extremities as shown. Two

by means of which the strips 61 may be tightly clamped against the sidewalls H to firmly retain the mirror 21 in any desired angular'position.When it is desired to clean or inspect the mirror 21, the light bulb 28or the lens 22, the wing nuts 12 are loosened and the mirror is tiltedbackward, being held in a horizontal position by the strips 51 engagingthe bolts 10 at the lower ends of the slots 69. After the requiredinspection, the mirror and frame are swung upwardly until the frame 35engages the heads of the adjustable set screws 65, when the wing nuts 12are again tightened, so retaining the mirror 21 and its frame 35 intheir upright position.

A particular feature of the light signal comprising the presentinvention is the accessibility of the parts of its light projectingunit. When it is desired to clean or inspect the mirror and the lightbulb, the door 9 is opened and'the spring latches 4| are swung outward,allowing the mirror 21 to be swung backward for exposing the bulb 28 andthe color screen 22. The mirror and the lenses may now be cleaned andthe light bulb replaced without disturbing the focus adjustment.

This accessibility of the light projecting unit parts is of greatimportance in railway signal work as it reduces the time required formaintenance to a minimum.

As the color light signal comprising the present invention has beendescribed in a rather specific form and'in connection with a specifictype of casing and supporting structure, it should be clearly understoodthat the invention is not limited in its scope to the particularstructures shown, and that certain changes and modifications can be madewithout departing from the spirit of the invention as defined by theappended claims.

What it is desired to secure by Letters Patent 1. In a light signal, incombination, a casing, a lens supporting ring secured to the casing, alens in the ring, a shelf on the ring and extending into the casing, alight source, means for supmeans for supporting the light source on the.

shelf, a concave reflector, means securing the re flector to the shelf,means for positioning the light source at the focal point of thereflector, and means for adjusting the reflector to project a beamthrough the lens.

SALISBURY M. DAY.

